Abstract: A process for etching a silicon layer disposed on a substrate, including anisotropically etching a first trench in the silicon layer; selectively anisotropic wet etching silicon surfaces in the first trench, the wet etching comprising exposing the silicon surfaces to an aqueous composition including an aromatic tri(lower)alkyl quaternary onium hydroxide, and an unsymmetrical tetraalkyl quaternary phosphonium salt; in which the wet etching etches (110) and (100) planes of the silicon layer at about equal rates and preferentially to the (111) plane to form an enlarged trench having a sidewall in the (111) plane. A silicon alloy may be epitaxially deposited in the thus-produced trench as part of a process of introducing stress into at least a portion of the silicon layer.

Abstract: A process for etching a silicon layer disposed on a substrate, including anisotropically etching a first trench in the silicon layer; selectively anisotropic wet etching silicon surfaces in the first trench, the wet etching comprising exposing the silicon surfaces to an aqueous composition including an aromatic tri(lower)alkyl quaternary onium hydroxide, and an unsymmetrical tetraalkyl quaternary phosphonium salt; in which the wet etching etches (110) and (100) planes of the silicon layer at about equal rates and preferentially to the (111) plane to form an enlarged trench having a sidewall in the (111) plane. A silicon alloy may be epitaxially deposited in the thus-produced trench as part of a process of introducing stress into at least a portion of the silicon layer.

Abstract: The present invention relates to a wet etching composition including a sulfonic acid, a phosphonic acid, a phosphinic acid or a mixture of any two or more thereof, and a fluoride, and to a process of selectively etching oxides relative to nitrides, high-nitrogen content silicon oxynitride, metal, silicon or silicide. The process includes providing a substrate comprising oxide and one or more of nitride, high-nitrogen content silicon oxynitride, metal, silicon or silicide in which the oxide is to be etched; applying to the substrate for a time sufficient to remove a desired quantity of oxide from the substrate the etching composition; and removing the etching composition, in which the oxide is removed selectively.

Abstract: Composition and a process using the composition for selectively wet etching metal including depositing metal on a silicon surface; applying energy to cause respective portions of the metal and silicon to form silicide, leaving a quantity of unreacted metal; selectively wet etching the unreacted metal by applying to the unreacted metal a composition including HCl, HBr, an ammonium halide, an amine hydrohalide salt, a quaternary ammonium halide, a quaternary phosphonium halide or a mixture of any two or more thereof; a nitrogen oxide compound; a stabilizer for the nitrogen oxide, comprising a glycol, a glyme, an ether, a polyol or a mixture of any two or more thereof; and water. In one embodiment, the composition includes an ammonium halide, an amine hydrohalide salt, a quaternary ammonium halide, a quaternary phosphonium halide or a mixture of any two or more thereof; a nitrogen oxide compound; and water.

Abstract: Composition for cleaning or etching a semiconductor substrate and method for using the same. The composition may include a fluorine-containing compound as an active agent such as a quaternary ammonium fluoride, a quaternary phosphonium fluoride, sulfonium fluoride, more generally an -onium fluoride or “multi” quaternary -onium fluoride that includes two or more quaternary- onium groups linked together by one or more carbon-containing groups. The composition may further include a pH adjusting acid such as a mineral acid, carboxylic acid, dicarboxylic acid, sulfonic acid, or combination thereof to give a pH of about 2 to 9. The composition can be anhydrous and may further include an organic solvent such as an alcohol, amide, ether, or combination thereof. The composition are useful for obtaining improved etch rate, etch selectivity, etch uniformity and cleaning criteria on a variety of substrates.

Abstract: Composition for cleaning or etching a semiconductor substrate and method for using the same. The composition may include a fluorine-containing compound as an active agent such as a quaternary ammonium fluoride, a quaternary phosphonium fluoride, sulfonium fluoride, more generally an -onium fluoride or “multi” quaternary-onium fluoride that includes two or more quaternary-onium groups linked together by one or more carbon-containing groups. The composition may further include a pH adjusting acid such as a mineral acid, carboxylic acid, dicarboxylic acid, sulfonic acid, or combination thereof to give a pH of about 2 to 9. The composition can be anhydrous and may further include an organic solvent such as an alcohol, amide, ether, or combination thereof. The composition are useful for obtaining improved etch rate, etch selectivity, etch uniformity and cleaning criteria on a variety of substrates.